The Effects of Coupling and Grounding on the Partial Discharge Pulse Propagation in the Underground Cable

When a Partial Discharge (PD) pulse propagates through a cross-bonded (CB) power cable system, such pulse undergoes attenuation and dispersion along a cable. Moreover, the coupling effect occurs when a PD pulse propagates in HV cable joints and CB link lines. This paper aims to study the effects of coupling phenomena and groundings on the PD pulse propagation. The experiments were divided into 3 parts: the experiment for attenuation in the conductor and ground wire, the experiment for coupling effect, and the experiment for different grounding configuration. The experimental setups used a 30 m length of new 33 kV XLPE insulated cable. PD pulses was obtained from a PD calibrator, and the pulses are detected by Radio Frequency Current Transformer at various positions. The knowledge gained from this research should be useful for a deep understanding of pulse propagation and PD source localization in CB power cable systems.